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mrange /
Last active May 20, 2019
[F#/OCaml] Implementing a data streams library using a bunch of one-liners

[F#/OCaml] Implementing a data streams library using a bunch of one-liners

A few years ago when I read the presentation motivating the design behind Nessos Streams I was struck by the beauty of simplistic push streams.

type PushStream<'T> = ('T -> bool) -> bool

LINQ (in .NET) is a pull stream, ie we pull values out of the stream by calling MoveNext + Current. One of the problems with pull streams is the constant checking "Are we done?" at each level in the stream.


Quick Tips for Fast Code on the JVM

I was talking to a coworker recently about general techniques that almost always form the core of any effort to write very fast, down-to-the-metal hot path code on the JVM, and they pointed out that there really isn't a particularly good place to go for this information. It occurred to me that, really, I had more or less picked up all of it by word of mouth and experience, and there just aren't any good reference sources on the topic. So… here's my word of mouth.

This is by no means a comprehensive gist. It's also important to understand that the techniques that I outline in here are not 100% absolute either. Performance on the JVM is an incredibly complicated subject, and while there are rules that almost always hold true, the "almost" remains very salient. Also, for many or even most applications, there will be other techniques that I'm not mentioning which will have a greater impact. JMH, Java Flight Recorder, and a good profiler are your very best friend! Mea

zmts /
Last active Nov 15, 2019
Про токены, JSON Web Tokens (JWT), аутентификацию и авторизацию. Token-Based Authentication

Про токены, JSON Web Tokens (JWT), аутентификацию и авторизацию. Token-Based Authentication

Last major update: 21.10.2019


Аутентификация(authentication, от греч. αὐθεντικός [authentikos] – реальный, подлинный; от αὐθέντης [authentes] – автор) - это процесс проверки учётных данных пользователя (логин/пароль). Проверка подлинности пользователя путём сравнения введённого им логина/пароля с данными сохранёнными в базе данных.

Авторизация(authorization — разрешение, уполномочивание) - это проверка прав пользователя на доступ к определенным ресурсам.

Например после аутентификации юзер sasha получает право обращатся и получать от ресурса "" некие данные. Во время обращения юзера sasha к ресурсу vip система авторизации проверит имеет ли право юзер обращатся к этому ресурсу (проще говоря переходить по неким разрешенным ссылкам)

JacobBennett /
Last active Oct 15, 2019
Clean up your Vue modules with ES6 Arrow Functions

Recently when refactoring a Vue 1.0 application, I utilized ES6 arrow functions to clean up the code and make things a bit more consistent before updating to Vue 2.0. Along the way I made a few mistakes and wanted to share the lessons I learned as well as offer a few conventions that I will be using in my Vue applications moving forward.

The best way to explain this is with an example so lets start there. I'm going to throw a rather large block of code at you here, but stick with me and we will move through it a piece at a time.


// require vue-resource...

new Vue({

Applied Functional Programming with Scala - Notes

Copyright © 2016-2018 Fantasyland Institute of Learning. All rights reserved.

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x
remarkablemark / Dockerfile
Last active Nov 14, 2019
Install node and npm with nvm using Docker.
View Dockerfile
# set the base image to Debian
FROM debian:latest
# replace shell with bash so we can source files
RUN rm /bin/sh && ln -s /bin/bash /bin/sh
# update the repository sources list
# and install dependencies
RUN apt-get update \
androidfred /
Last active Nov 13, 2019
Haskell, Stack and Intellij IDEA IDE setup tutorial how to get started

Haskell, Stack and Intellij IDEA IDE setup tutorial how to get started

Upon completion you will have a sane, productive Haskell environment adhering to best practices.


  • Haskell is a programming language.
  • Stack is tool for Haskell projects. (similar tools for other languages include Maven, Gradle, npm, RubyGems etc)
  • Intellij IDEA IDE is a popular IDE.

Install required libraries

sudo apt-get install libtinfo-dev libghc-zlib-dev libghc-zlib-bindings-dev

View sample.scala
import scalaz._
import scalaz.std.list._
import scalaz.syntax.monad._
import scalaz.syntax.monoid._
import scalaz.syntax.traverse.{ToFunctorOps => _, _}
class Foo[F[+_] : Monad, A, B](val execute: Foo.Request[A] => F[B], val joins: Foo.Request[A] => B => List[Foo.Request[A]])(implicit J: Foo.Join[A, B]) {
def bar: Foo[({type l[+a]=WriterT[F, Log[A, B], a]})#l, A, B] = {
type TraceW[FF[+_], +AA] = WriterT[FF, Log[A, B], AA]
namiazad / To Byte Sequence Converter.scala
Last active Feb 9, 2018
A Scala DSL to convert data to a byte sequence representation
View To Byte Sequence Converter.scala
import{ByteArrayOutputStream, DataOutputStream}
import shapeless._
case class Container(dos: DataOutputStream, baos: ByteArrayOutputStream) {
def ~[A: ByteSequenceRepr](arg: A) = implicitly[ByteSequenceRepr[A]].toByteSequence(this, arg)
def ~| : Array[Byte] = {
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